"O'Reilly's suggestion that no one ever complained about his behavior is false," she said. "I know, because I complained."

Kelly said she'd emailed Bill Shine and Jack Abernethy, co-presidents of Fox News, about O'Reilly's alleged conduct, urging them to take action and change Fox's culture of "shaming women into shutting the hell up about harassment."

NBC published a copy of the email on Monday afternoon. In it, Kelly accuses O'Reilly of silencing women and suggesting that coming forward about misconduct would "disgrace the company."

That logic "is in part how Fox News got into the decade-long Ailes mess to begin with," Kelly wrote.

"This must stop," Kelly said Monday. "The abuse of women, the shaming of them, the threatening and the retaliation, the silencing them after the fact — it has to stop."

"Women everywhere are used to being dismissed, ignored or attacked when raising complaints about men in authority positions," she went on. "They stay silent so often out of fear ― fear of ending their careers, fear of lawyers, yes, and often fear of public shaming, including through the media."

Fox issued a statement in response to Kelly, saying the network "has taken concerted action" to change.

I asked 21st Century Fox for its reaction to Megyn Kelly monologue of this morning criticizing O'Reilly, Briganti & Co. pic.twitter.com/ud6FoBBgFc